MetaSim is a suite of easy-to-use software authoring tools, which enable authors of internet-based medical educational materials to develop interactive case-based simulation examples. Case-based simulation examples have long been a mainstay of medical education, and their use is increasingly encouraged. However, because of technological complexities that make highly interactive content such as simulators much more difficult to create than standard text or videotaped lectures, they are uncommon in web-based educational practice. The mantra of MetaSim is to make simple a task that is currently quite complex: this includes educational simulations in Internet medical education. PROPOSED COMMERCIAL APPLICATION: NIST (1998) estimates that in the health care industry more than 10 million workers and professionals require training at a cost of $5-6 billion per year. Specifically, the market for education presented over the internet is expected to grow greatly, inluding basic medical education and continuing medical education (CME/CEU). At this point, business models for internet education are still in flux, though we anticipate that our initial customers will include internet-based continuing education consolidators such as HealthStream (www.healthstream.com) and CME Gateway (www. cmegateway.com).